a little of help :D

args = { ... }
length = args[1] or 1
height = args[2] or 1
diameter = args[3] or 1
print("Wall builder running...")
for l = 1, length do
for f = 1, diameter do
turtle.forward()
end
for p = 1, diameter do
turtle.place()
turtle.back()
end
for h = 2, height do
turtle.up()
for f = 1, diameter do
turtle.forward()
end
for p = 1, diameter do
turtle.place()
turtle.back()
end
end
for d = 2, height do
turtle.down()
end
turtle.turnRight()
turtle.forward()
turtle.turnLeft()
end
print("Wall done!")